Module Board

ABSTRACT

A module board has a configuration in which a first circuit board, a first composite sheet, a second circuit board, a second composite sheet, and a third circuit board are laminated in this order. Inspection terminals are arranged in a matrix shape in a predetermined region on an upper surface of the third circuit board. Electronic components are mounted on the first and second circuit boards. The inspection terminals are electrically connected to the electronic components mounted on the first and second circuit boards through vias and wiring patterns.

TECHNICAL FIELD

The present invention relates to a module board having an electroniccomponent such as an LSI (Large Scale Integrated Circuit) or an IC(Integrated Circuit) mounted thereon.

BACKGROUND ART

In recent years, digital appliances such as digital televisions havebeen spreading in general homes. To make products sophisticated andmultifunctional holds the key to the spread of the digital appliances.

The performance of the digital appliances can be improved by increasingthe speed of digital signal processing. To increase the speed of thedigital signal processing can be realized by improving the clockfrequencies of system LSIs, expanding the widths of data buses, andusing high-speed memories such as DDR (Double Data Rate) memories, forexample.

Furthermore, in order to increase the functions of the digitalappliances, the high integration densities of circuits are required. Toincrease the integration densities of the circuits can be realized byplacing a plurality of electronic components within one package bytechniques such as MCM (Multi Chip Module) or SIP (System In Package),for example.

Although a large number of functions can be carried in the products byincreasing the integration densities of the circuits, however, thenumber of interface signals required for the respective functions tooperate also increases. Thus, the number of external terminals providedoutside the package also increases. As the number of electroniccomponents accommodated within the package increases, the number ofexternal terminals for inspecting the electronic components alsoincreases. Although the package is electrically connected to externalboards through the external terminals, the increase in the number ofexternal terminals makes it difficult to miniaturize the package.

In an IC package in Patent Document 1, for example, therefore, alower-stage lead terminal is provided on the first layer of a lead boardhaving a double-layer structure, and an upper-stage lead terminalserving as a testing terminal is provided on the second layer thereof.In this configuration, the upper-stage lead terminal provided on thesecond layer of the lead board is not connected to the circuit board.That is, the testing terminal is provided on the second layer of thelead terminal, to reduce the number of terminals to be provided in aregion (on the first layer of the lead board) to which the circuit boardis connected. This makes it conceivable that the IC package can beminiaturized.

[Patent Document 1] JP 2000-68440 A

DISCLOSURE OF THE INVENTION [Problems to be Solved by the Invention]

In the configuration of the IC package in Patent Document 1, describedabove, however, the lead board must have a double-layer structure inorder to provide the testing terminal. In this case, a board, which isnot functionally required, serving as an electronic component isprovided, so that the manufacturing cost and the number of manufacturingprocesses increase.

Since the testing terminal is formed on the second layer of the leadboard, the length of a wire for connecting the testing terminal and anIC chip increases. In this case, it is difficult to provide impedancematching between the testing terminal and the IC chip. This causes areflected wave to be generated at the testing terminal or an end of thewire when the IC chip is inspected, so that a waveform strain is inducedin an inspection signal. As a result, it is difficult to accuratelyinspect the IC chip.

[Means for Solving the Problems]

An object of the present invention is to provide a small-sized moduleboard that can reliably inspect an electronic component and themanufacturing cost of which is prevented from increasing.

(1)

A module board according to an aspect of the present invention includesa plurality of circuit boards laminated in the vertical direction andeach having a wiring pattern, one or a plurality of electroniccomponents mounted on at least one of the plurality of circuit boardsand electrically connected to the wiring pattern, a first terminalprovided on a lower surface of the lowermost one of the plurality ofcircuit boards and electrically connected to the wiring pattern, and asecond terminal provided so as to be exposed to an upper surface of anyone of the plurality of circuit boards and electrically connected to thewiring pattern.

In the module board, the plurality of circuit boards each having thewiring pattern are laminated in the vertical direction. The one orplurality of electronic components electrically connected to the wiringpattern are mounted on at least one of the plurality of circuit boards.The first terminal electrically connected to the wiring pattern isprovided on the lower surface of the lowermost one of the plurality ofcircuit boards. The second terminal electrically connected to the wiringpattern is provided so as to be exposed to the upper surface of any oneof the plurality of circuit boards.

In this case, the second terminal is exposed to the upper surface of thecircuit board. In a state where the module board is mounted on theexternal board through the first terminal, therefore, an inspectiondevice can be connected to the second terminal. This allows an internalcircuit of the electronic component and a signal of the electroniccomponent to be inspected with the module board mounted on the externalboard. As a result, a defect in the electronic component within themodule board can be reliably detected.

The second terminal is formed on any one of the plurality of circuitboards, which eliminates the need to provide a separate board forforming the second terminal. This can prevent the manufacturing cost ofthe module board from increasing.

Furthermore, the first terminal is formed on the lower surface of thecircuit board, and the second terminal is formed on the upper surface ofthe circuit board. That is, the first and second terminals arerespectively formed on the different surfaces of the circuit board. Inthis case, the size of the circuit board for forming the first andsecond terminals can be prevented from increasing. This allows themodule board to be miniaturized.

(2)

At least one of the one or plurality of electronic components may besealed.

In this case, the sealed electronic component is cut off from outsideair. This causes the electronic component from being protected fromexternal influences. As a result, the electronic component can beprevented from being damaged and degraded.

(3)

A space may be formed within the plurality of circuit boards, at leastone of the one or plurality of electronic components may be arranged inthe space, and the space may be sealed.

In this case, the electronic component is arranged in the sealed space,so that the electronic component is cut off from outside air. Thiscauses the electronic component from being protected from externalinfluences. As a result, the electronic component can be prevented frombeing damaged and degraded.

(4)

The second terminal may be electrically connected to the wiring patternthrough a conductor penetrating at least one of the circuit boards.

In this case, the second terminal and the wiring pattern can be easilyconnected to each other. Further, respective capacitive components andinductive components of wiring between the second terminal and aplurality of wiring patterns can be reduced. This can prevent a waveformstrain to be induced in an inspection signal inputted to the electroniccomponent. Further, apart of the conductor can be used as the secondterminal, so that the manufacturing cost of the module board can bereduced.

(5)

The second terminal may be provided in a partial region on the uppersurface of the uppermost one of the plurality of circuit boards.

In this case, an inspection device can be easily connected to the secondterminal from above the module board. This allows a defect in theelectronic component within the module board to be easily detected.

(6)

The module board may further comprise a sealing layer formed on aregion, excluding the partial region, on the upper surface of theuppermost circuit board.

In this case, the sealing layer cuts off the electronic component fromoutside air. This causes the electronic component to be protected fromexternal influences. As a result, the electronic component can beprevented from being damaged and degraded.

(7)

The second terminal may be provided in a partial region on the uppersurface of any one of the circuit boards, excluding the uppermostcircuit board, out of the plurality of circuit boards, and a space maybe formed above the partial region.

In this case, an inspection device can be easily connected to the secondterminal from the space. This allows a defect in the electroniccomponent within the module board to be easily detected. Further, thecircuit board positioned above the circuit board on which the secondterminal is formed protects the second terminal from externalinfluences. Therefore, the second terminal can be prevented from beingdamaged and degraded.

(8)

The other one or plurality of circuit boards positioned above the anyone of the circuit board may have a concave (cut-out, notch, orincision) or an opening such that the second terminal is exposed.

In this case, an inspection device can be easily connected to the secondterminal from above the module board through the concave or the opening.This allows a defect in the electronic component within the module boardto be easily detected. Further, the second terminal is protected fromexternal influences by being surrounded by an inner wall of the concaveor the opening. Therefore, the second terminal can be prevented frombeing damaged and degraded.

(9)

The module board may further comprise an insulating layer providedbetween at least two of the plurality of circuit boards, the secondterminal may be formed in the partial region on the upper surface of thecircuit board below the insulating layer, and the insulating layer mayhave a concave or an opening such that the second terminal is exposed.

In this case, an inspection device can be easily connected to the secondterminal through the concave or the opening. This allows a defect in theelectronic component within the module board to be easily detected.Further, the second terminal is protected from external influences bybeing surrounded by an inner wall of the concave or the opening.Therefore, the second terminal can be prevented from being damaged anddegraded.

(10)

The module board may further comprise grounding conductor layersrespectively provided on the upper surface or the lower surface of theuppermost circuit board and the lower surface of the lowermost circuitboard.

In this case, the grounding conductor layer can prevent high-frequencynoises radiated from the electronic component and the wiring patternfrom leaking out of the module board. This can prevent electronicequipment from being erroneously operated.

(11)

The first and second terminals may respectively comprise a plurality offirst terminals and a plurality of second terminals, and the size ofeach of the plurality of second terminals may be smaller than the sizeof each of the plurality of first terminals.

In this case, a region where the second terminal is formed on thecircuit board can be reduced, so that a region where an electroniccomponent is to be mounted and a region where a wiring pattern is to beformed can be enlarged. This allows the packaging density of theelectronic component on the module board to be improved and allows themodule board to be miniaturized.

High-frequency noises can be prevented from being radiated to theoutside of the module board from the second terminal by reducing thesize of the second terminal. This can reliably prevent electronicequipment from being erroneously operated.

(12)

The pitch between the plurality of second terminals may be smaller thanthe pitch between the plurality of first terminals.

In this case, the region where the second terminal is formed on thecircuit board can be reduced, so that a region where an electroniccomponent is to be mounted and a region where a wiring pattern is to beformed can be enlarged. This allows the packaging density of theelectronic component on the module board to be improved and allows themodule board to be miniaturized.

(13)

The plurality of second terminals may be arranged in a matrix shape.

In this case, the region where the second terminal is formed on thecircuit board can be reduced, so that a region where an electroniccomponent is to be mounted and a region where a wiring pattern is to beformed can be enlarged. This allows the packaging density of theelectronic component on the module board to be improved and allows themodule board to be miniaturized.

(14)

The second terminal may be arranged in a region along at least one sideof the any circuit board.

In this case, a region where an electronic component is to be mountedand a region where a wiring pattern is to be formed can be sufficientlyensured at the center of the circuit board. This allows the packagingdensity of the electronic component on the module board to be improvedand allows the module board to be miniaturized.

(15)

The second terminal is arranged at the center of the any circuit board.In this case, the inspection terminal is protected from externalinfluences. Therefore, the inspection terminal can be prevented frombeing damaged and degraded.

(16)

The one or plurality of electronic components may include first andsecond electronic components, the first and second electronic componentsmay be electrically connected to each other by the wiring pattern formedon at least one of the circuit boards, excluding the uppermost circuitboard, out of the plurality of circuit boards, and the second terminalmay be electrically connected to the wiring pattern for electricallyconnecting the first and second electronic components.

In this case, a signal, which is transferred between the first andsecond electronic components and is not outputted to the outside of themodule board, can be inspected by connecting an inspection device to thesecond terminal. This allows the state of the electronic componentwithin the module board to be specifically detected.

(17)

The one or plurality of electronic components and the wiring pattern mayconstitute a circuit for achieving a predetermined function, the firstterminal may include a plurality of external terminals connected to thecircuit, and the second terminal may include a plurality of inspectionterminals for inspecting the circuit or any of the electroniccomponents.

In this case, the circuit within the module board can be electricallyconnected to the external board through the external terminals. Further,the circuit and the electronic component can be inspected through theinspection terminals.

(18)

The one or plurality of electronic components may include a firstelectronic component and a plurality of second electronic components,the wiring pattern may include a first wiring part connected to thefirst electronic component and a plurality of second wiring partsbranching off from the first wiring part and respectively connected tothe plurality of second electronic components, and the plurality ofinspection terminals may be connected to the plurality of second wiringparts.

In this case, a signal that is transferred between the first and secondelectronic components can be reliably inspected by connecting aninspection device to the inspection terminals.

(19)

The plurality of second wiring parts may have an equal length. In thiscase, a reflected wave can be prevented from being generated at thesecond terminal. This can prevent a waveform strain from being inducedin the signal transferred between the first and second electroniccomponents.

(20)

Each of the plurality of second electronic components may be a storagedevice.

In this case, the number of bits composing the signal processed by thefirst electronic component can be expanded depending on the number ofstorage devices electrically connected to the first electroniccomponent. This allows the performance of the module board to beimproved using a low-cost storage device with a small number of bits.

[Effects of the Invention]

According to the present invention, the second terminal is exposed tothe upper surface of the circuit board. In a state where the moduleboard is mounted on the external board through the first terminal,therefore, the inspection device can be connected to the secondterminal. This makes it possible to inspect the internal circuit of theelectronic component and the signal of the electronic component with themodule board mounted on the external board. As a result, the defect inthe electronic component within the module board can be reliablydetected.

The second terminal is formed on any one of the plurality of circuitboards, which eliminates the need to provide a separate board forforming the second terminal. Consequently, the manufacturing cost of themodule board can be prevented from increasing.

The first terminal is formed on the lower surface of the circuit board,and the second terminal is formed on the upper surface of the circuitboard. That is, the first terminal and the second terminal arerespectively formed on the different surfaces of the circuit board.Further, the size of the second terminal and the pitch between thesecond terminals can be made sufficiently smaller, respectively, thanthe size of the first terminal and the pitch between the firstterminals. In this case, it is possible to prevent increase of the sizeof the circuit board due to forming of the first and second terminals.This allows the module board to be miniaturized.

In a case where the plurality of electronic components are contained,the plurality of second terminals are connected to the plurality ofelectronic components connected to the first electronic component by theplurality of second wiring parts having an equal length. The respectivewiring lengths from the connection position to the plurality of secondterminals are equal to one another. Consequently, a reflected wave canbe prevented from being generated at the plurality of second terminals.This can prevent a waveform strain from being induced in a signal of thewiring pattern. Further, each of the electronic components and thewiring pattern between the electronic components are accommodatedbetween the grounding conductor layers formed within the module board.Therefore, the radiation of high-frequency noises generated by each ofthe electronic components and the wiring pattern is inhibited byshielding. Further, the size of the second terminal can be sufficientlyreduced. This can prevent the cost of inhibiting waveform strains andthe cost of shielding in the module board from increasing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the appearance of a module boardaccording to a first embodiment.

FIG. 2 is a diagram for explaining the internal configuration of themodule board.

FIG. 3 is a diagram schematically showing wiring patterns formed on afirst board.

FIG. 4 is a perspective view showing the appearance of a module boardaccording to a second embodiment.

FIG. 5 is a diagram for explaining the internal configuration of themodule board shown in FIG. 4.

FIG. 6 is a perspective view showing the appearance of a module boardaccording to a third embodiment.

FIG. 7 is a diagram for explaining the internal configuration of themodule board shown in FIG. 6.

FIG. 8 is a perspective view showing the appearance of a module boardaccording to a fourth embodiment.

FIG. 9 is a diagram for explaining the internal configuration of themodule board shown in FIG. 8.

FIG. 10 is a perspective view showing the appearance of a module boardaccording to a fifth embodiment.

FIG. 11 is a perspective view showing the appearance of a module boardaccording to a sixth embodiment.

FIG. 12 is a perspective view showing the appearance of a module boardaccording to a seventh embodiment.

FIG. 13 is a perspective view showing the appearance of a module boardaccording to an eighth embodiment.

FIG. 14 is a diagram showing an example of the relationship between anLSI and inspection terminals.

FIG. 15 is a diagram showing an example of the relationship between anLSI and a memory and inspection terminals.

FIG. 16 is a diagram showing another example of the relationship betweenan LSI and a memory and inspection terminals.

BEST MODE FOR CARRYING OUT THE INVENTION

Module boards according to the embodiments of the present invention willbe described below while referring to the drawings.

(1) First Embodiment

(a) Configuration

FIG. 1 is a perspective view showing the appearance of a module boardaccording to a first embodiment. FIG. 1 is accompanied by arrows thatrespectively indicate X, Y, and Z directions perpendicular to oneanother for clarity of a positional relationship. The X and Y directionsare perpendicular to each other within a horizontal plane, and the Zdirection corresponds to a vertical direction. FIG. 2 and FIGS. 4 to 13,described later, are similarly accompanied by arrows that respectivelyindicate X, Y, and Z directions.

As shown in FIG. 1, a module board 100 according to the presentembodiment has a configuration in which a first circuit board 11(hereinafter abbreviated as a first board 11), a first composite sheet21, a second circuit board 12 (hereinafter abbreviated as a second board12), a second composite sheet 22, and a third circuit board 13(hereinafter abbreviated as a third board 13) are laminated in thisorder. An IC (Integrated Circuit) 31 is mounted on the third board 13.Note that each of the first to third boards 11 to 13 may be a multilayerboard or a single layer board. Usable as the first and second compositesheets 21 and 22 is an adhesive sheet including epoxy resin. Forexample, a prepreg can be used. Each of the first and second compositesheets assumes a role of an insulating layer.

A first inspection portion 410 and a second inspection portion 420 arerespectively provided in predetermined regions along two sides in the Ydirection on an upper surface of the third board 13. A plurality ofinspection terminals 41 and a plurality of inspection terminals 42 arerespectively arranged in a matrix shape in the first and secondinspection portions 410 and 420.

The inspection terminals 41 and 42 are respectively electricallyconnected to electronic components such as LSIs mounted on the first andsecond boards 11 and 12 through wiring patterns, as described later. Anexample of the inspection terminals 41 and 42 is a land or a via. Aninspection probe of an inspection device (not shown) is connected to theinspection terminals 41 and 42. The details will be described later.

A plurality of solder balls 43 are formed on a lower surface of thefirst board 11. The solder balls 43 are respectively electricallyconnected to the electronic components mounted on the first to thirdboards 11 to 13.

The module board 100 is mounted on an external board (not shown) bybeing soldered using the solder balls 43. This causes the external boardand the electronic components mounted on the module board 100 to beelectrically connected to each other. The module board 100 is mounted onthe external board by a reflow soldering method, for example.

Note that the inspection terminals 41 and 42 need not be soldered by thereflow soldering method because they need not be connected to theexternal board. Therefore, each of the inspection terminals 41 and 42may be of such a size that the inspection probe of the inspection device(not shown) can come into contact therewith. In this case, the size ofeach of the inspection terminals 41 and 42 can be sufficiently reduced,and the pitch between the inspection terminals 41 and the pitch betweenthe inspection terminals 42 can be sufficiently reduced.

Consequently, the size of each of the inspection terminals 41 and 42 canbe made sufficiently smaller than the size of the solder balls 43.Further, the pitch between the inspection terminals 41 and the pitchbetween the inspection terminals 42 can be made sufficiently smallerthan the pitch between the solder balls 43. For example, the size of thesolder balls 43 is approximately 650 μm, and the size of each of theinspection terminals 41 and 42 is approximately 100 μm. For example, thepitch between the solder balls 43 is 1 mm, and the pitch between theinspection terminals 41 is 150 μm.

The internal configuration of the module board 100 will be described indetail below.

FIG. 2 is a diagram for explaining the internal configuration of themodule board 100. FIG. 2( a) is a diagram showing the positionalrelationship on an XY plane of a plurality of electronic componentsmounted on the module board 100, and FIG. 2( b) is a cross-sectionalview of the module board 100.

As shown in FIG. 2( b), a space 51 vertically penetrating the firstcomposite sheet 21 is formed at the center of the first composite sheet21. An LSI (Large Scale Integrated Circuit) 32, a memory 33, and amemory 34 are mounted on the first board 11 within the space 51. Each ofthe memories 33 and 34 is a work memory that functions as a work area ofthe LSI 32. An example of the memories 33 and 34 is a DDR (Double DataRate) memory. In this case, a signal having a high frequency of not lessthan 400 MHz can be transferred between the LSI 32 and the memories 33and 34.

Furthermore, a space 52 vertically penetrating the second compositesheet 22 is formed in the second composite sheet 22. An LSI 35 ismounted on the second board 12 within the space 52.

Note that the space 51 is cut off from outside air by the firstcomposite sheet 21 and the second board 12. That is, the LSI 32 and thememories 33 and 34 are mounted in the sealed space 51. Thus, the LSI 32and the memories 33 and 34 can be protected from external influences,and can be prevented from being damaged and degraded. On the other hand,the space 52 is cut off from outside air by the second composite sheet22 and the third board 13. That is, the LSI 35 is mounted in the sealedspace 52. Thus, the LSI 35 can be protected from external influences,and can be prevented from being damaged and degraded. In the spaces 51and 52, a sealing layer such as a thin-film mold may be further providedso as to cover the LSI 32 and the memories 33 and 34.

The LSI 32, the memories 33 and 34, and the LSI 35 are made to adhere onthe first board 11 and the second board 12 through an adhesive sheet(not shown) having a thickness of several micrometer, for example. TheLSI 32, the memories 33 and 34, and the LSI 35 are electricallyconnected to the first board 11 and the second board 12 by a wirebonding technology or a flip-chip technology, for example.

The respective heights on the first board 11 of the LSI 32, the memory33, and the memory 34 and the respective heights on the second board 12of the LSI 32, the memory 33, and the memory 34 can be kept low by usingthe wire bonding technology or the flip-chip technology. This allows therespective thicknesses of the first and second composite sheets 21 and22 to be reduced and allows the module board 100 to be thinned.

In FIG. 2, the LSI 32 and the memories 33 and 34 are electricallyconnected to the wiring pattern on the first board 11 by the wirebonding technology, and the LSI 35 is electrically connected to thewiring pattern on the second board 12 by the flop-chip technology. Notethat the IC 31 is mounted on the third board 13 so that the heightthereof need not be kept low. Consequently, the IC 31 can beelectrically connected to a wiring pattern (not shown) on the thirdboard 13 by the reflow soldering method.

Note that usable as the LSI 32, the memories 33 and 34, and the LSI 35is a bare die ground and diced to a predetermined size or a CSP (ChipSize Package), for example. It is preferable that the thickness of eachof the first and second composite sheets 21 and 22 is larger than thethickness of the bare die or the CSP, for example, 50 μm to 800 μm.

As shown in FIG. 2( b), grounding conductor layers ECL, which are notillustrated in FIG. 1, are respectively formed on the lower surface ofthe first board 11 and the upper surface and the lower surface of thethird board 13.

The grounding conductor layer ECL is formed in a region, excludingregions where the solder balls 43 are respectively formed, on the lowersurface of the first board 11. The grounding conductor layer ECL isformed in a region, excluding regions where the inspection terminals 41and 42 are respectively formed, a region where the IC 31 is mounted, anda region where a wiring pattern (not shown) is formed, on the uppersurface of the third board 13. The grounding conductor layer ECL isformed in a region, excluding regions where vias 411, 412, and 421 to423 are respectively formed, on the lower surface of the third board 13.Note that it is preferable that the grounding conductor layers ECL areformed in the regions, which are as wide as possible, so as not to comeinto contact with the solder balls 43, the inspection terminals 41 and42, the IC 31, the wiring pattern, and the vias 411, 412, and 421 to423. The effect of the grounding conductor layers ECL will be describedlater.

Here, as shown in FIG. 2( a), the LSI 32, the memories 33 and 34, theLSI 35, and the inspection terminals 41 and 42 are electricallyconnected to one another by wiring patterns 111 to 116 formed on thefirst board 11 and a wiring pattern 117 formed on the second board 12.Description is now made of wiring among the LSI 32, the memories 33 and34, and the inspection terminals 41 and 42 will be described whilefurther referring to FIG. 3.

FIG. 3 is a diagram schematically showing the wiring patterns 111 to 116formed on the first board 11. Although the respective one wiringpatterns 111 to 117 are typically illustrated in FIG. 2, each of thewiring patterns 111 to 117 actually comprises a plurality of wiringpatterns. Similarly, although the respective one vias 411, 412, and 421to 423 are typically illustrated in FIG. 2, each of the vias 411, 412,and 421 to 423 actually comprises a plurality of vias.

As shown in FIG. 3, one ends of the plurality of wiring patterns 111 arerespectively electrically connected to a plurality of terminals of theLSI 32 through a plurality of bonding pads 322 (FIG. 2( a)) and aplurality of wires 321 (FIG. 2( a)). The other ends of the plurality ofwiring patterns 111 are respectively connected to the centers of theplurality of wiring patterns 112.

One ends of the plurality of wiring patterns 112 are respectivelyelectrically connected to a plurality of terminals of the memory 33through bonding pads 332 (FIG. 2( a)) and wires 331 (FIG. 2( a)). Theother ends of the plurality of wiring patterns 112 are respectivelyelectrically connected to a plurality of terminals of the memory 34through bonding pads 342 (FIG. 2( a)) and wires 341 (FIG. 2( a)).

As shown in FIG. 3, one ends of the plurality of wiring patterns 113 arerespectively electrically connected to the plurality of inspectionterminals 41 through the via 411 (FIG. 2( b)) formed near one side inthe Y direction of the module board 100 (FIG. 2( b)). The other ends ofthe plurality of wiring patterns 113 are respectively connected to theplurality of wiring patterns 112. Thus, the wiring pattern 113 is stubwiring branching off from the wiring pattern 112. This causes theinspection terminals 41 to be electrically connected to the wiringpatterns 111 and 112.

Furthermore, one ends of the plurality of wiring patterns 114 arerespectively electrically connected to a plurality of inspectionterminals 42 through the via 421 (FIG. 2( b)) formed near the other sidein the Y direction of the module board 100 (FIG. 2( b)). The other endsof the plurality of wiring patterns 114 are respectively connected tothe plurality of wiring patterns 112. Thus, the wiring pattern 114 isstub wiring branching off from the wiring pattern 112. This causes theinspection terminals 42 to be electrically connected to the wiringpatterns 111 and 112.

One ends of the plurality of wiring patterns 115 are respectivelyelectrically connected to the plurality of terminals of the LSI 32through the bonding pads 322 (FIG. 2( a)) and the wires 321 (FIG. 2(a)). The other ends of the plurality of wiring patterns 115 arerespectively electrically connected to the plurality of terminals of thememory 33 through the bonding pads 332 (FIG. 2( a)) and the wires 331(FIG. 2( a)).

Furthermore, the plurality of wiring patterns 115 are respectivelyelectrically connected to the plurality of inspection terminals 41through the via 412 (FIG. 2( b)) formed near one side in the Y directionof the module board 100 (FIG. 2( b)). This causes the inspectionterminals 41 to be electrically connected to the wiring patterns 115.

One ends of the plurality of wiring patterns 116 are respectivelyelectrically connected to the plurality of terminals of the LSI 32through the bonding pads 322 (FIG. 2( a)) and the wires 321 (FIG. 2(a)). The other ends of the plurality of wiring patterns 116 arerespectively electrically connected to the plurality of terminals of thememory 34 through the bonding pads 342 (FIG. 2( a)) and the wires 341(FIG. 2( a)).

Furthermore, the plurality of wiring patterns 116 are respectivelyelectrically connected to the plurality of inspection terminals 42through the via 422 (FIG. 2( b)) formed near the other side in the Ydirection of the module board 100 (FIG. 2( b)). This causes theinspection terminals 42 to be electrically connected to the wiringpatterns 116.

By the above-mentioned configuration, an address signal and a clocksignal are transferred to the memories 33 and 34 from the LSI 32 throughthe wiring patterns 111 and 112. Further, a data signal is transferredbetween the LSI 32 and the memories 33 and 34 through the wiringpatterns 115 and 116.

Here, the wiring patterns 111, 112, 115, and 116 are functionally wiringthat is only required for connecting the LSI 32 and the memories 33 and34. That is, the wiring patterns 111, 112, 115, and 116 through whicheach of the signals is transferred are functionally sufficient forwiring for connecting the LSI 32 and the memories 33 and 34. The wiringpatterns 111, 112, 115, and 116 are cut off from outside air by thefirst composite sheet 21 and the second board 12. That is, the LSI 32,the memories 33 and 34, and the wiring patterns 111, 112, 115, and 116are sealed into the module board 100.

In order to inspect the waveform and pattern of each of the signalstransferred to the memories 33 and 34 from the LSI 32, an inspectiondevice (not shown) must be connected to the wiring patterns 111, 112,115, and 116 sealed into the module board 100. In order to inspectrespective internal circuits of the LSI 32 and the memories 33 and 34,inspection signals must be inputted to the LSI 32 and the memories 33and 34 from outside the module board 100, respectively, to collatesignals outputted from the LSI 132 and the memories 33 and 34 with theirexpected values.

In the present embodiment, therefore, the inspection terminals 41 arerespectively electrically connected to the wiring patterns 111 and 112,as described in FIGS. 2 and 3. This causes the respective waveforms andpatterns of the address signal and the clock signal transferred to thememory 33 from the LSI 32 to be inspected by connecting the inspectiondevice (not shown) to the inspection terminals 41.

The inspection terminals 42 are respectively electrically connected tothe wiring patterns 111 and 112. This causes the respective waveformsand patterns of the address signal and the clock signal transferred tothe memory 34 from the LSI 32 to be inspected by connecting theinspection device (not shown) to the inspection terminals 42.

The inspection terminals 41 are respectively electrically connected tothe wiring patterns 115. This causes the waveform and pattern of thedata signal transferred between the LSI 32 and the memory 33 to beinspected by connecting the inspection device (not shown) to theinspection terminals 41.

The inspection terminals 42 are respectively electrically connected tothe wiring patterns 116. This causes the waveform and pattern of thedata signal transferred between the LSI 32 and the memory 34 to beinspected by connecting the inspection device (not shown) to theinspection terminals 42.

When the respective internal circuits of the LSI 32 and the memories 33and 34 are inspected, inspection signals can be inputted thereto fromthe inspection terminals 41 and 42, respectively, to collate signalsoutputted from the inspection terminals 41 and 42 with their expectedvalues.

As shown in FIG. 2, the LSI 35 is electrically connected to theinspection terminals 42 through the wiring patterns 117 and the via 423(FIG. 2( b)) in the module board 100. Consequently, it is possible toinspect an internal circuit of the LSI 35 and its signal, as in the LSI32 and the memories 33 and 34, by connecting the inspection device (notshown) to the inspection terminals 42.

In the present embodiment, each of the common address signal and clocksignal outputted from the LSI 32 through the wiring patterns 111branches off in two directions by the wiring patterns 112, and signalsobtained by the branching are respectively inputted to the memories 33and 34.

In this case, when data signals each composed of six bits arerespectively transferred to the memories 33 and 34 from the LSI 32 inFIG. 3, for example, the 6-bit data signals are respectively stored instorage areas designated by the common address signal in the memories 33and 34. Consequently, the data signals composed of a total of 12 bitscan be read and written out of and into the memories 33 and 34 using thecommon address signal and clock signal. That is, the number of bitscomposing the data signal processed by the LSI 32 can be expanded to twotimes. This allows the performance of the module board 100 to beimproved using a low-cost memory.

In the present embodiment, the wiring pattern 113 and the wiring pattern114 that are connected to the same wiring pattern 112 are formed to havean equal length. The wiring pattern 111 is connected to the positionwhere the wiring pattern 112 is divided into two equal parts. Further,the via 411 and the via 421 are formed to have an equal length.Consequently, the wiring length from the connection position to theinspection terminal 41 and the wiring length from the connectionposition to the inspection terminal 42 become equal to each other.

In order to inspect signals to be respectively transferred to the wiringpatterns 111 and 112, one inspection terminal is inherently sufficientfor one set of wiring patterns 111 and 112 to be connected. When onestub wiring is pulled out of each of the wiring patterns 111 or each ofthe wiring patterns 112 and is connected to the inspection terminal,however, a reflected wave is generated at the inspection terminal, sothat a waveform strain is induced in the signal.

In the present embodiment, therefore, the two wiring patterns 113 and114 branching off from each of the wiring patterns 112 connect the twoinspection terminals 41 and 42 for the set of wiring patterns 111 and112 to be connected. The respective lengths of the wiring patterns 113and 114 branching off from the same wiring pattern 112 are made equal toeach other. Further, the wiring pattern 111 is connected to the positionwhere the wiring pattern 112 is divided into two equal parts. This canprevent reflected waves from being respectively generated at theinspection terminals 41 and 42. As a result, waveform strains can beprevented from being respectively induced in the address signal and theclock signal.

Note that the wiring patterns 113 and 114 may branch off from not thewiring pattern 112 but the wiring pattern 111.

Furthermore, the number of memories connected to the LSI 32 is notlimited to two. Three or more memories may be connected in parallel. Inthis case, it is possible to further expand the number of bits composingthe data signal processed by the LSI 32.

In the configuration shown in FIG. 3, the wiring pattern connected tothe LSI 32 branches off in two directions. When the number of memoriesis set to three or more, the wiring pattern connected to the LSI 32 isformed so as to branch off in the same number of directions as thenumber of memories. In this case, when inspection terminals arerespectively connected to wiring patterns obtained by the branching, itis preferable that the wiring patterns are formed such that therespective wiring lengths from a branching point to the inspectionterminals are equal to each other, as in the above-mentioned case. Thiscan prevent a reflected wave from being generated at each of theinspection terminals.

As described in the foregoing, the grounding conductor layers ECL arerespectively formed in the regions that are as wide as possible on thelower surface of the first board 11 and the upper surface and the lowersurface of the third board 13. This allows the LSIs 32 and 35, thememories 33 and 34, and the wiring patterns 111 to 117 connected theretoto be accommodated between the grounding conductor layers ECL. In thiscase, the grounding conductor layers ECL can prevent high-frequencynoises radiated from the LSIs 32 and 35, the memories 33 and 34, and thewiring patterns 111 to 117 from leaking out of the module board 100.

As described in the foregoing, the size of each of the inspectionterminals 41 and 42 can be sufficiently reduced. In this case, thehigh-frequency noises can be prevented from being radiated to theoutside of the module board 100 from the inspection terminals 41 and 42.

As a result of these, the high-frequency noises can be reliablyprevented from being radiated from the module board 100. This canprevent electronic equipment from being erroneously operated.

(b) Effect

As described in the foregoing, in the present embodiment, the inspectionterminals 41 and 42 are provided on the third board 13. In this case,even in a state where the module board 100 is mounted on the externalboard, it is possible to inspect the internal circuit of each of theelectronic components (the LSIs 32 and 35 and the memories 33 and 34)mounted in the module board 100 and the signal of the electroniccomponent using the inspection terminals 41 and 42. This allows a defectin each of the electronic components in the module board 100 to bereliably detected.

Signals, which are not inherently outputted to the outside of the moduleboard 100, for example, the signals between the LSI 32 and the memories33 and 34 (address signal, clock signal, and data signal), can beinspected. This allows the state of each of the electronic components inthe module board 100 to be specifically inspected.

Furthermore, the inspection terminals 41 and 42 are electricallyconnected to the electronic components through the wiring patterns 111to 117 and the vias 411, 412, and 421 to 423. In this case, there is noneed to use wires for connecting the electronic components to theinspection terminals 41 and 42 in addition to the wires 321, 331, and341 for connecting the electronic components to the wiring patterns 111to 117.

Consequently, the respective lengths of the wires between each of theelectronic components and the inspection terminals 41 and 42 can bereduced. In a case where the inspection signals are respectivelyinputted to the inspection terminals 41 and 42 from the inspectiondevice, therefore, waveform strains can be prevented from beingrespectively induced in the inspection signals. As a result, theinternal circuit of the electronic component can be accuratelyinspected.

Particularly when each of the electronic components is mounted on thefirst and second boards 11 and 12 by the flip-chip technology, there isno need to use a wire for mounting the electronic component. This allowsimpedance matching between each of the electronic components and theinspection terminals 41 and 42 to be more accurately provided.

The inspection terminals 41 and 42 are electrically connected to the LSI32 and the memories 33 and 34 through the wiring patterns 111 to 114 andthe vias 411 and 421. The wiring pattern 113 and the wiring pattern 114that are connected to the same wiring pattern 112 are formed so as tohave an equal length. Further, the wiring pattern 111 is connected tothe position where the wiring pattern 112 is divided into two equalparts. Consequently, the wiring length from the connection position tothe inspection terminals 41 and the wiring length from the connectionposition to the inspection terminals 42 become equal to each other. Thiscan prevent reflected waves from being respectively generated at theinspection terminals 41 and 42. As a result, waveform strains can beprevented from being respectively induced in the address signal and theclock signal.

The inspection terminals 41 and 42 are provided on the third board 13 onwhich the IC 31 is mounted. That is, the inspection terminals 41 and 42are provided on the board on which the electronic component is to bemounted, which eliminates the need to provide a separate board forproviding the inspection terminals 41 and 42. Consequently, themanufacturing cost of the module board 100 can be prevented fromincreasing.

The respective wiring lengths between each of the electronic componentsand the inspection terminals 41 and 42 can be reduced by providing theinspection terminals 41 and 42 on the third board 13. This allowsrespective capacitive components and inductive components between eachof the electronic components and the inspection terminals 41 and 42 tobe reduced. As a result, a waveform strain can be reliably preventedfrom being induced in the inspection signal inputted to each of theelectronic components.

The inspection terminals 41 and 42 are arranged on the upper surface onboth sides of the third board 13. In this case, a region where anelectronic component is to be mounted and a region where a wiringpattern is to be formed can be sufficiently ensured at the center ofeach of the first to third boards 11 to 13. This allows the packagingdensity of the electronic component in the module board 100 to beimproved and allows the module board 100 to be miniaturized.

The size of each of the inspection terminals 41 and 42, the pitchbetween the inspection terminals 41, and the pitch between theinspection terminals 42 are sufficiently small. This allows a regionwhere an electronic component is to be mounted and a region where awiring pattern is to be formed to be further enlarged. As a result, itis possible to sufficiently improve the packaging density of theelectronic component in the module board 100 as well as to sufficientlyminiaturize the module board 100.

Each of the electronic components (the LSIs 32 and 35 and the memories33 and 34) and the wiring patterns 111 to 117 between the electroniccomponents can be accommodated between the grounding conductor layersECL with a predetermined pattern. This can prevent the high-frequencynoises radiated from each of the electronic components and the wiringpatterns 111 to 117 from leaking out of the module board 100.

Furthermore, the size of each of the inspection terminals 41 and 42 canbe sufficiently reduced. This can prevent the high-frequency noises frombeing radiated to the outside of the module board 100 from theinspection terminals 41 and 42.

As a result of these, the high-frequency noises can be prevented frombeing radiated from the module board 100 without taking special measuresfor removing the high-frequency noises. This can reliably prevent theelectronic equipment from being erroneously operated.

As a result of the foregoing, it is possible to prevent the cost ofinhibiting the waveform strains in the module board 100 and the cost ofpreventing the leakage of the high-frequency noises from increasing.

(c) Another Configuration

The arrangement shape of the inspection terminals 41 and 42 is notlimited to that in the example shown in FIG. 1. For example, theplurality of inspection terminals 41 and 42 may be arranged along aperipheral edge of the third board 13. In this case, a region where anelectronic component is to be mounted and a region where a wiringpattern is to be formed can be also sufficiently ensured at the centerof each of first to third boards 11 to 13.

Although description was made of the case where only the LSI 35 ismounted on the second board 12 in FIG. 2, a plurality of electroniccomponents may be mounted on the second board 12. For example, threeelectronic components may be mounted on the second board 12, as on thefirst board 11.

A circuit board may be used in place of each of the first and secondcomposite sheets 21 and 22. In this case, wiring patterns can be formedon the circuit board, which allows more electronic components to bemounted on the module board 100.

In a case where the first and second composite sheets 21 and 22 arerespectively replaced with circuit boards, the circuit boards may beformed integrally with the first board 11, the second board 12, or thethird board 13.

(2) Second Embodiment

A module board according to a second embodiment differs from the moduleboard according to the first embodiment (FIGS. 1 to 3) in the followingpoints.

FIG. 4 is a perspective view showing the appearance of the module board101 according to the second embodiment. FIG. 5 is a diagram forexplaining the internal configuration of the module board 101 shown inFIG. 4. FIG. 5( a) is a diagram showing the positional relationship onan XY plane of a plurality of electronic components mounted on themodule board 101, and FIG. 5( b) is a cross-sectional view of the moduleboard 101.

As shown in FIGS. 4 and 5, in the module board 101 according to thepresent embodiment, rectangular concaves (cut-outs, notches, orincisions) 430 and 440 are respectively formed in predetermined regionsof a second composite sheet 22 and a third board 13 such thatpredetermined regions along two sides in the Y direction on an uppersurface of a second board 12 are exposed. Further, a first inspectionportion 410 and a second inspection portion 420 are respectivelyprovided in regions, exposed within the concaves 430 and 440, on theupper surface of the second board 12.

Note that the concaves 430 and 440 may be formed by previously cuttingaway the respective predetermined regions of the second composite sheet22 and the third board 13. Alternatively, the concaves 430 and 440 maybe formed by cutting away the respective predetermined regions of thesecond composite sheet 22 and the third board 13 after the first tothird boards 11 to 13 and the first and second composite sheets 21 and22 are laminated.

In the present embodiment, inspection terminals 41 and 42 are providedon the second board 12, as shown in FIG. 5( b). Therefore, vias forrespectively connecting each of the electronic components and theinspection terminals 41 and 42 need not be formed on the secondcomposite sheet 22 and the third board 13. This allows the manufacturingcost of the module board 101 to be reduced.

A wiring pattern 117 and the inspection terminal 42 on the second board12 can be connected to each other on the second board 12. In this case,the wiring length between an LSI 35 and the inspection terminal 42 canbe sufficiently reduced. This allows an inductive component and acapacitive component between the LSI 35 and the inspection terminal 42to be sufficiently reduced. As a result, a waveform strain can beprevented from being induced in an inspection signal inputted to the LSI35.

Since the inspection terminals 41 and 42 are provided on the secondboard 12, the respective wiring lengths from an LSI 32 and memories 33and 34 to the inspection terminals 41 and 42 can be sufficientlyreduced. This allows respective inductive components and capacitivecomponents between the LSI 32 and the inspection terminals 41 and 42 andbetween the memories 33 and 34 and the inspection terminals 41 and 42 tobe sufficiently reduced. As a result, waveform strains can be reliablyprevented from being respectively induced in inspection signals inputtedto the LSI 32 and the memories 33 and 34.

As shown in FIG. 4, the first and second inspection portions 410 and420, excluding their one sides, are surrounded by the second compositesheet 22 and the third board 13. In this case, the inspection terminals41 and 42 are protected by the second composite sheet 22 and the thirdboard 13. Therefore, the inspection terminals 41 and 42 can be preventedfrom being damaged and degraded.

Note that the concave 430 and the concave 440 may be respectively formedin each of predetermined regions of the first composite sheet 21, thesecond board 12, the second composite sheet 22, and the third board 13such that a predetermined region on an upper surface of the first board11 is exposed.

In this case, the first inspection portion 410 and the second inspectionportion 420 can be respectively provided in regions, exposed within theconcaves 430 and 440, on the upper surface of the first board 11. Inthis configuration, the respective wiring lengths from the LSI 32 andthe memories 33 and 34 to the inspection terminals 41 and 42 can bereliably reduced. Note that the LSI 35 and the inspection terminals 41and 42 can be electrically connected to each other by forming vias inthe second board 12 and the first composite sheet 21.

(3) Third Embodiment

A module board according to a third embodiment differs from the moduleboard 100 according to the first embodiment (FIGS. 1 to 3) in thefollowing points.

FIG. 6 is a perspective view showing the appearance of the module board102 according to the third embodiment. FIG. 7 is a diagram forexplaining the internal configuration of the module board 102 shown inFIG. 6. FIG. 7( a) is a diagram showing the positional relationship onan XY plane of a plurality of electronic components mounted on themodule board 102, and FIG. 7( b) is a cross-sectional view of the moduleboard 102.

As shown in FIG. 6, in the module board 102 according to the presentembodiment, a first board 11, a first composite sheet 21, and a secondboard 12 are laminated in this order. First and second inspectionportions 410 and 420 are respectively provided in predetermined regionsalong two sides in the Y direction of the second board 12.

As shown in FIG. 7( b), grounding conductor layers ECL are respectivelyformed on an upper surface and a lower surface of the second board 11,which is not illustrated in FIG. 6.

On an upper surface of the second board 12, a grounding conductor layerECL is formed in a region excluding regions where the inspectionterminals 41 and 42 are respectively formed. On a lower surface of thesecond board 12, a grounding conductor layer ECL is formed in a regionexcluding regions where vias 411, 412, and 421 to 423 are respectivelyformed.

Furthermore, as shown in FIG. 7( b), a hole 53 is formed in apredetermined region at the center of the second board 12. As shown inFIGS. 6 and 7, a molded member 61 serving as a sealing layer is formedso as to seal a space 51 and the hole 53. This allows an LSI 32 andmemories 33 and 34 to be protected from external influences, which canprevent them from being damaged and degraded. The molded member 61 iscomposed of a resin material, for example.

In the present embodiment, inspection terminals 41 and 42 are providedon the second board 12, as shown in FIG. 7( b). Therefore, therespective wiring lengths from the LSI 32 and memories 33 and 34 to theinspection terminals 41 and 42 can be sufficiently reduced. This allowsrespective inductive components and capacitive components between theLSI 32 and the inspection terminals 41 and 42 and between the memories33 and 34 and the inspection terminals 41 and 42 to be sufficientlyreduced. As a result, waveform strains can be reliably prevented frombeing respectively induced in inspection signals inputted to the LSI 32and the memories 33 and 34.

The inspection terminals 41 and 42 are provided on the second board 12on which an electronic component can be mounted. That is, the inspectionterminals 41 and 42 are provided on a circuit board on which anelectronic component is to be mounted, which eliminates the need toprovide a separate circuit board for providing the inspection terminals41 and 42. Consequently, the manufacturing cost of the module board 102can be prevented from increasing.

Note that the first composite sheet 21 may be replaced with a circuitboard. In this case, a wiring pattern can be formed on the circuitboard, more electronic components can be mounted on the module board102.

When the first composite sheet 21 is replaced with a circuit board, thecircuit board may be formed integrally with the first board 11 or thesecond board 12.

(4) Fourth Embodiment

A module board according to a fourth embodiment differs from the moduleboard 102 according to the third embodiment (FIGS. 6 and 7) in thefollowing points.

FIG. 8 is a perspective view showing the appearance of the module board103 according to the fourth embodiment. FIG. 9 is a diagram forexplaining the internal configuration of the module board 103 shown inFIG. 8. FIG. 9( a) is a diagram showing the positional relationship onan XY plane of a plurality of electronic components mounted on themodule board 103, and FIG. 9(b) is a cross-sectional view of the moduleboard 103.

As shown in FIGS. 8 and 9, in the module board 103 according to thepresent embodiment, rectangular concaves 430 and 440 are respectivelyformed in predetermined regions of a first composite sheet 21 and asecond board 12 such that predetermined regions along two sides in the Ydirection on an upper surface of a first board 11 are exposed. Further,a first inspection portion 410 and a second inspection portion 420 arerespectively provided in regions, exposed within the concaves 430 and440, on the upper surface of the first board 11.

In the present embodiment, inspection terminals 41 and 42 are providedon the first board 11, as shown in FIG. 9( b). Therefore, vias forrespectively electrically connecting each of the electronic componentsand the inspection terminals 41 and 42 need not be formed on the firstcomposite sheet 21 and the second board 12. This allows themanufacturing cost of the module board 103 to be reduced.

Since the inspection terminals 41 and 42 are provided on the first board11, the respective wiring lengths from an LSI 32 and memories 33 and 34to the inspection terminals 41 and 42 can be sufficiently reduced. Thisallows respective inductive components and capacitive components betweenthe LSI 32 and the inspection terminals 41 and 42 and between thememories 33 and 34 and the inspection terminals 41 and 42 to besufficiently reduced. As a result, waveform strains can be reliablyprevented from being respectively induced in inspection signals inputtedto the LSI 32 and the memories 33 and 34.

The first and second inspection portions 410 and 420, excluding theirone sides, are surrounded by the first composite sheet 21 and the secondboard 12. In this case, the inspection terminals 41 and 42 are protectedby the first composite sheet 21 and the second board 12. Therefore, theinspection terminals 41 and 42 can be prevented from being damaged anddegraded.

(5) Fifth Embodiment

A module board according to a fifth embodiment differs from the moduleboard 100 according to the first embodiment (FIGS. 1 to 3) in thefollowing points.

FIG. 10 is a perspective view showing the appearance of the module boardaccording to the fifth embodiment.

As shown in FIG. 10, the module board 104 according to the presentembodiment has a configuration in which a first board 11, a firstcomposite sheet 21, and a second board 12 are laminated in this order.First and second inspection portions 410 and 420 are respectivelyprovided in predetermined regions along two sides in the Y direction ofthe second board 12. Further, an LSI 32 and memories 33 and 34 aremounted, as in FIG. 2( b), on the first board 11.

Since inspection terminals 41 and 42 are provided on the second board 12in the present embodiment, the respective wiring lengths from the LSI 32and the memories 33 and 34 to the inspection terminals 41 and 42 can besufficiently reduced. This allows respective inductive components andcapacitive components between the LSI 32 the inspection terminals 41 and42 and between and the memories 33 and 34 and the inspection terminals41 and 42 to be sufficiently reduced. As a result, waveform strains canbe reliably prevented from being respectively induced in inspectionsignals inputted to the LSI 32 and the memories 33 and 34.

(6) Sixth Embodiment

A module board according to a sixth embodiment differs from the moduleboard 104 according to the fifth embodiment (FIG. 10) in the followingpoints.

FIG. 11 is a perspective view showing the appearance of the module boardaccording to the sixth embodiment.

As shown in FIG. 11, in the module board 105 according to the presentembodiment, rectangular concaves 430 and 440 are respectively formed inpredetermined regions of a first composite sheet 21 and a second board12 such that predetermined regions along two sides in the Y direction onan upper surface of a first board 11 are exposed. Further, a firstinspection portion 410 and a second inspection portion 420 arerespectively provided in regions, exposed within the concaves 430 and440, on the upper surface of the first board 11.

In the present embodiment, inspection terminals 41 and 42 are providedon the first board 11. Therefore, vias for respectively electricallyconnecting each of electronic components and the inspection terminals 41and 42 need not be formed in the first composite sheet 21 and the secondboard 12. This allows the manufacturing cost of the module board 105 tobe reduced.

Since the inspection terminals 41 and 42 are provided on the first board11, the respective wiring lengths from an LSI 32 and memories 33 and 34to the inspection terminals 41 and 42 can be sufficiently reduced. Thisallows respective inductive components and capacitive components betweenthe LSI 32 and the inspection terminals 41 and 42 and between thememories 33 and 34 and the inspection terminals 41 and 42 to besufficiently reduced. As a result, waveform strains can be reliablyprevented from being respectively induced in inspection signals inputtedto the LSI 32 and the memories 33 and 34.

The first and second inspection portions 410 and 420, excluding theirone sides, are surrounded by the first composite sheet 21 and the secondboard 12. In this case, the inspection terminals 41 and 42 are protectedby the first composite sheet 21 and the second board 12. Therefore, theinspection terminals 41 and 42 can be prevented from being damaged anddegraded.

(7) Seventh Embodiment

A module board according to a seventh embodiment differs from the moduleboard 105 according to the sixth embodiment (FIG. 11) in the followingpoints.

FIG. 12 is a perspective view showing the appearance of the module boardaccording to the seventh embodiment.

As shown in FIG. 12, in the module board 106 according to the presentembodiment, rectangular concaves 430 and 440 are respectively formed inpredetermined regions of a first composite sheet 21 such thatpredetermined regions along two sides in the Y direction on an uppersurface of a first board 11 are exposed. Further, a first inspectionportion 410 and a second inspection portion 420 are respectivelyprovided in regions, exposed within the concaves 430 and 440, on theupper surface of the first board 11.

In this case, respective upper surfaces of the first and secondinspection portions 410 and 420 are protected by a second board 12.Therefore, inspection terminals 41 and 42 can be reliably prevented frombeing damaged and degraded.

Since no concave is formed in the second board 12, a region where anelectronic component is to be mounted and a region where a wiringpattern is to be formed can be sufficiently ensured on the second board12.

(8) Eighth Embodiment

A module board according to an eighth embodiment differs from the moduleboard 104 according to the fifth embodiment (FIG. 10) in the followingpoints.

FIG. 13 is a perspective view showing the appearance of the module boardaccording to the eighth embodiment.

As shown in FIG. 13, in the module board 107 according to the presentembodiment, a rectangular opening 450 is formed at the respectivecenters of a first composite sheet 21 and a second board 12 such that apredetermined region on an upper surface of a first board 11 is exposed.Further, a plurality of inspection terminals 45 are arranged in a matrixshape in a region on the upper surface of the first board 11 exposedwithin the opening 450. Note that the inspection terminals 45 areconnected to each of electronic components, as in the above-mentionedembodiments.

In the present embodiment, the inspection terminals 45 are provided onthe first board 11. Therefore, a via for electrically connecting each ofthe electronic components and the inspection terminals 45 need not beformed in the first composite sheet 21 and the second board 12. Thisallows the manufacturing cost of the module board 107 to be reduced.

Since the inspection terminals 45 are provided on the first board 11,the respective wiring lengths from an LSI 32 and memories 33 and 34 tothe inspection terminals 45 can be sufficiently reduced. This allowsrespective inductive components and capacitive components between theLSI 32 and the inspection terminals 41 and 42 and between the memories33 and 34 and the inspection terminals 45 to be sufficiently reduced. Asa result, waveform strains can be reliably prevented from beingrespectively induced in inspection signals inputted to the LSI 32 andthe memories 33 and 34.

The inspection terminals 45 are surrounded by the first composite sheet21 and the second board 12. In this case, the inspection terminals 45are protected by the first composite sheet 21 and the second board 12.Therefore, the inspection terminals 45 can be prevented from beingdamaged and degraded.

(9) Another Embodiment

Although description was made of a case where the LSI 32 and thememories 33 and 34 are electrically connected to each other on the firstboard 11 in the above-mentioned embodiments, a plurality of electroniccomponents mounted on the first board 11 may be respectively mounted inan electrically independent manner.

FIG. 14 is a diagram showing an example of the relationship between anLSI 32 and inspection terminals 41 or 42 in a case where the LSI 32 ismounted on the first board 11 in an electrically independent manner fromother electronic components.

In FIG. 14, a plurality of terminals of the LSI 32 and a plurality ofsolder balls 43 are electrically connected, respectively, by a pluralityof wiring patterns 118. This causes the LSI 32 and a circuit of anexternal board to be electrically connected to each other. Also in thefirst embodiment, the LSI 32 and the solder balls 43 are electricallyconnected, as in FIG. 14, which is not illustrated in FIG. 3.

The plurality of terminals of the LSI 32 and the plurality of inspectionterminals 41 or 42 are electrically connected, respectively, by aplurality of wiring patterns 119. Consequently, it is possible toinspect an internal circuit of the LSI 32 and its signal, as in theabove-mentioned embodiments, by using the inspection terminals 41 or 42.

FIG. 15 is a diagram showing an example of the relationship between anLSI 32 and a memory 33 and inspection terminals 41 or 42 in a case wherethe LSI 32 and the memory 33 are electrically connected to each other ona first board 11.

In FIG. 15, the LSI 32 is electrically connected to solder balls 43, asin FIG. 14. Further, a plurality of terminals of the LSI 32 and aplurality of terminals of the memory 33 are electrically connected,respectively, by a plurality of wiring patterns 120. This causes the LSI32 and the memory 33 to be electrically connected to each other.

The inspection terminals 41 or 42 are respectively formed on the wiringpatterns 120. Consequently, it is possible to inspect respectiveinternal circuits of the LSI 32 and the memory 33 and their signals, asin the above-mentioned embodiments, by using the inspection terminals 41or 42. In this example, the respective wiring lengths from the LSI 32and the memory 33 to the inspection terminals 41 or 42 can besufficiently reduced. This can reliably prevent waveform strains frombeing respectively induced in inspection signals inputted to the LSI 32and the memory 33.

FIG. 16 is a diagram showing another example of the relationship betweenan LSI 32 and a memory 33 and inspection terminals 41 or 42 in a casewhere the LSI 32 and the memory 33 are electrically connected to eachother and mounted on a first board 11.

The example shown in FIG. 16 differs from the example shown in FIG. 15in the following points.

In FIG. 16, the inspection terminals 41 or 42 are electricallyconnected, respectively, to wiring patterns 120 by wiring patterns 121.Thus, the wiring pattern 121 is stub wiring branching off from thewiring pattern 120. Also in this case, it is possible to inspectrespective internal circuits of the LSI 32 and the memory 33 and theirsignals by using the inspection terminals 41 or 42, as in FIG. 15. Inthis example, respective output signals of the LSI 32 and the memory 33are pulled out by the wiring patterns 121. Therefore, the wiringpatterns 120 can be formed in any path without being affected by thepositions of the inspection terminals 41 or 42. Consequently, the degreeof freedom of wiring is increased.

The number of electronic components mounted on each of the first tothird boards 11 to 13 is not limited to the number described in theabove-mentioned embodiments. More electronic components may be mountedon each of the first to third boards 11 to 13. Alternatively, one or twoelectronic components may be mounted on each of the first to thirdboards 11.

Although description was made of a case where two or three circuitboards are laminated in the above-mentioned embodiments, four or morecircuit boards may be laminated. In this case, the electronic componentsmay be also arranged on each of the circuit boards, and inspectionterminals 41 or 42 or inspection terminals 45 may be arranged so as tobe exposed upward, as in the above-mentioned embodiments. This allowsrespective internal circuits of the electronic components and theirsignals to be inspected with a module board mounted on an externalboard.

Although each of the electronic components is mounted on the uppersurface of each of the boards in the above-mentioned embodiments, theelectronic components may be mounted on a lower surface or on bothsurfaces of each of the boards.

Although the inspection terminals 41 and 42 are provided on the samecircuit board in the above-mentioned embodiments, the inspectionterminals 41 and 42 may be respectively provided on the differentcircuit boards. For example, the inspection terminals 41 may be providedon the first board 11, and the inspection terminals 42 may be providedon the second board 12.

Although description was made of a module board of a BGA (Ball GridArray) type in the above-mentioned embodiments, connector terminals maybe provided in place of the solder balls 43 to electrically connect themodule board and the external board to each other.

Although description was made of the respective cases where therectangular concaves 430 and 440 and the rectangular opening 450 areprovided, the respective shapes of the concaves 430 and the 440 and theopening 450 are not limited to those in the above-mentioned examples.For example, they may be in another shape such as a circular shape, anelliptical shape, or a polygonal shape. Further, three or more concavesor openings may be formed.

The respective positions where the concaves 430 and 440 and the opening450 are formed are not limited to those in the above-mentioned examples.For example, they may be formed at the center on a side surface of themodule board. Alternatively, they may be formed at four corners of themodule board.

Although description was made of the case where the rectangularinspection portions 410 and 420 are provided, the shape of theinspection portions 410 and 420 is not limited to those in theabove-mentioned examples. For example, it may be in another shape suchas a circular shape, an elliptical shape, or a polygonal shape. Further,three or more inspection portions 410 or 420 may be formed.

The respective positions where the inspection portions 410 and 420 areformed are not limited to those in the above-mentioned examples. Forexample, they may be formed at the center on an upper surface of themodule board, or formed at the center on a side surface of the moduleboard. Alternatively, they may be formed at four corners of the moduleboard.

(10) Correspondences Between Elements in the Claims and Parts inEmbodiments

In the following paragraph, non-limiting examples of correspondencesbetween various elements recited in the claims below and those describedabove with respect to various preferred embodiments of the presentinvention are explained.

In the embodiments described above, the solder ball 43 corresponds to afirst terminal and an external terminal, the inspection terminals 41,42, and 45 correspond to a second terminal, the molded member 61corresponds to a sealing layer, the first and second composite sheets 21and 22 correspond to an insulating layer, the LSI 32 corresponds to afirst electronic component, the memories 33 and 34 correspond to asecond electronic component, the wiring pattern 111 corresponds to afirst wiring part, the wiring patterns 112 to 114 correspond to a secondwiring part, and the vias 411, 412, and 421 to 423 correspond to aconductor penetrating a circuit board.

INDUSTRIAL APPLICABILITY

The present invention is applicable to various types of electricequipment or electronic equipment, for example.

1-19. (canceled)
 20. A module board comprising: a plurality of circuitboards laminated in the vertical direction and each having a wiringpattern; one or a plurality of electronic components mounted on at leastone of said plurality of circuit boards and electrically connected tosaid wiring pattern; a first terminal provided on a lower surface of thelowermost one of said plurality of circuit boards and electricallyconnected to said wring pattern; a second terminal provided on a partialregion on an upper surface of the uppermost one of said plurality ofcircuit boards and electrically connected to said wiring pattern; and asealing layer formed on a region, excluding said partial region, on theupper surface of said uppermost circuit board.
 21. The module boardaccording to claim 20, wherein said second terminal is electricallyconnected to said wiring pattern through a conductor penetrating atleast one of the circuit boards.
 22. The module board according to claim20, wherein said first and second terminals respectively comprise aplurality of first terminals and a plurality of second terminals, andthe pitch between said plurality of second terminals is smaller than thepitch between said plurality of first terminals.
 23. The module boardaccording to claim 20, wherein said one or plurality of electroniccomponents include first and second electronic components, said firstand second electronic components are electrically connected to eachother by the wiring pattern formed on at least one of said plurality ofcircuit boards, and said second terminal is electrically connected tothe wiring pattern for electrically connecting the first and secondelectronic components.
 24. The module board according to claim 20,wherein said second terminal includes a plurality of inspectionterminals for inspecting any one of the electronic components.
 25. Amodule board comprising: a plurality of circuit boards laminated in thevertical direction and each having a wiring pattern; one or a pluralityof electronic components mounted on at least one of said plurality ofcircuit boards and electrically connected to said wiring pattern; afirst terminal provided on a lower surface of the lowermost one of saidplurality of circuit boards and electrically connected to said wiringpattern; and a second terminal provided on a partial region on an uppersurface of any one of the circuit boards, excluding the uppermostcircuit board, out of said plurality of circuit boards and electricallyconnected to said wiring pattern, a space being formed above saidpartial region.
 26. The module board according to claim 25, wherein theother one or plurality of circuit boards positioned above said anycircuit board has a concave or an opening such that said second terminalis exposed.
 27. The module board according to claim 25, furthercomprising an insulating layer provided between at least two of saidplurality of circuit boards, said second terminal being formed on saidpartial region on the upper surface of the circuit board below saidinsulating layer, and said insulating layer having a concave or anopening such that said second terminal is exposed.
 28. The module boardaccording to claim 25, wherein said first and second terminalsrespectively comprise a plurality of first terminals and a plurality ofsecond terminals, and the pitch between said plurality of secondterminals is smaller than the pitch between said plurality of firstterminals.
 29. The module board according to claim 25, wherein saidsecond terminal is arranged at the center of said any circuit board. 30.The module board according to claim 25, wherein said one or plurality ofelectronic components include first and second electronic components,said first and second electronic components are electrically connectedto each other by the wiring pattern formed on at least one of saidplurality of circuit boards, and said second terminal is electricallyconnected to the wiring pattern for electrically connecting the firstand second electronic components.
 31. The module board according toclaim 25, wherein said second terminal includes a plurality ofinspection terminals for inspecting any of the electronic components.32. A module board comprising: a plurality of circuit boards laminatedin the vertical direction and each having a wiring pattern; one or aplurality of electronic components mounted on at least one of saidplurality of circuit boards and electrically connected to said wiringpattern; a first terminal provided on a lower surface of the lowermostone of said plurality of circuit boards and electrically connected tosaid wiring pattern; and a second terminal provided so as to be exposedto an upper surface of any one of said plurality of circuit boards andelectrically connected to said wiring pattern, said second terminalbeing arranged in a region along at least one side of said any circuitboard.
 33. The module board according to claim 32, wherein said firstand second terminals respectively comprise a plurality of firstterminals and a plurality of second terminals, and the pitch betweensaid plurality of second terminals is smaller than the pitch betweensaid plurality of first terminals.
 34. The module board according toclaim 32, wherein said one or plurality of electronic components includefirst and second electronic components, said first and second electroniccomponents are electrically connected to each other by the wiringpattern formed on at least one of said plurality of circuit boards, andsaid second terminal is electrically connected to the wiring pattern forelectrically connecting the first and second electronic components. 35.The module board according to claim 32, wherein said second terminalincludes a plurality of inspection terminals for inspecting any of theelectronic components.
 36. A module board comprising: a plurality ofcircuit boards laminated in the vertical direction and each having awiring pattern; a plurality of electronic components mounted on at leastone of said plurality of circuit boards and electrically connected tosaid wiring pattern; a first terminal provided on a lower surface of thelowermost one of said plurality of circuit boards and electricallyconnected to said wiring pattern; and a plurality of second terminalsprovided on any one of said plurality of circuit boards and electricallyconnected to said wiring pattern, and wherein said plurality ofelectronic components and said wiring pattern constitute a circuit forachieving a predetermined function, said first terminal includes aplurality of external terminals connected to said circuit, saidplurality of electronic components include a first electronic componentand a plurality of second electronic components, said wiring patternincludes a first wiring part connected to said first electroniccomponent and a plurality of second wiring parts branching off from saidfirst wiring part and respectively connected to said plurality of secondelectronic components, said plurality of second terminals arerespectively connected to said plurality of second wiring parts, andsaid plurality of second wiring parts have an equal length.
 37. Themodule board according to claim 36, wherein said plurality of secondterminals are provided so as to be exposed to the upper surface of saidany circuit board.
 38. The module board according to claim 36, whereinsaid plurality of second terminals include a plurality of inspectionterminals for inspecting said circuit or any of the electroniccomponents.